This invention relates generally to frying apparatus for continuous deep vat frying of large quantities of food products in large scale food processing systems, and more particularly to a treatment and filtration system for maintaining oil quality and integrity in conjunction with the fryer.
Large scale food processing systems may include large scale frying apparatus which allows a food processor to introduce a battered food product, batter-breaded or otherwise, and/or other coated or uncoated food products into a volume of frying oil for frying in a continuous processing line. Frying oil is generally contained in an elongated reservoir, and it is heated by suitable heaters, such as heating tubes, thermal fluid heat exchangers or direct fired heating as examples. One significant problem associated with such frying apparatus is the large volume of frying oil used and required for immersing the battered and/or breaded food products in the oil bath. These large volumes of oil are then exposed to the food itself and the food or coating particles dislodged from the food as it is conveyed through the fryer on a conveyor system. Additionally, other materials may be released from the food during the frying process which include starch grains, maillard reactants, caramelization reactants, fats and water and other materials. As these food particles, fats, starch grains, maillard reactants, caramelized reactants and water and other extraneous materials remain in the oil during the frying process, degradation of the oil quality occurs. Degradation of the physical and chemical properties of the frying oil can result in adverse tastes, colors, odors or the like in the food product being cooked. Also, the organoleptic qualities of the fried food products begin to degrade as the oil quality degrades, due to the maillard and caramelization reactions created as the food passes through the fryer, or from food particles dislodged, leached or otherwise removed from the food during cooking.
The processor faced with these concerns resorts to disposal of the volume of oil after relatively short frying cycles, and the reintroduction of another fresh volume of oil. It should be recognized that disposal of a large volume of oil from a continuous frying apparatus requires suitable facilities to properly dispose of the spent oil, and the reintroduction of oil into the frying apparatus to continue the cooking process. The changing of spent oil in the frying system necessarily reduces throughput of the cooking process significantly, and the volumes and associated costs of the cooking oil itself can become excessive. Extending the life of the frying oil would substantially reduce the volumes and cost of the cooking oil itself as well as time spent handling used oil and refreshing the frying system, thereby minimizing down time in the frying process.
In the frying process, cooking oil will eventually degrade, imparting unwanted tastes, odors and colors to the oil and food products fried therein, caused in part by the creation of free fatty acids in the cooking oil created when food particles remain in the oil. As the percentage of free fatty acids in the cooking oil increases, these unwanted characteristics also increase, along with the creation of smoke or possible fire, again causing significant problems or serious hazards.
It would therefore be extremely useful to prolong the usable life of cooking oil by reducing the formation of free fatty acids generated in the cooking process. Filtering the oil to remove food particles or other debris from the oil has been attempted, and attempts have also been made to treat the spent oil to reduce the percentage of free fatty acids therein in a separate treatment process once the oil is removed from the fryer. Although intended to provide some of the desired benefits, such attempts have not been fully successful. This results in part from inadequate removal of fine particles and the removal of large quantities of retained oil in any particulates removed from the oil.
Based upon the foregoing, it is an object of the invention to provide a frying system and process which greatly enhances oil quality and integrity during a frying cycle, and extends the useful life of the cooking oil to reduce the volumes of spent oil which must be discarded or otherwise disposed of.
The invention is therefore directed to an oil treatment apparatus and method for treatment of oil which comprises a source of oil to be treated coupled to a first conduit, and transporting oil from the source to a treatment station. The treatment station comprises a filter system capable of extracting particulate material from the oil and removing the particulate material from the filter system as it is removed from the oil. The treated oil may then be pumped for use in a continuous cycle with the source of the oil. Alternatively, the treatment system comprises a source of cooking oil communicating with the treatment station, wherein the treatment station receives cooking oil and includes a filter system which extracts particulates down to a size of approximately one micron. The cooking oil is preferably continuously supplied to the filter system and returned for use after the particulate material has been extracted.
These and other objects and advantages of the invention will become apparent upon a further reading of the detailed description of the invention in conjunction with the drawings.